We are currently measuring insulin binding, glucose transport, glucose metabolism, and lipolysis in adipocytes isolated from human subcutaneous abdominal tissue of Pima Indians. Subjects with normal glucose tolerance and with two nondiabetic parents or one diabetic parent have also been studied. In addition, subjects with glucose intolerance or diabetes have been studied as part of a cross sectional study in the Pima Indians. We have shown that adipocytes from diabetic subjects have altered adipocyte metabolism (i.e. transport, metabolism and lipolysis without any change in insulin binding). We are currently attempting to measure glucose intolerant individuals to see if the changes in adipocyte metabolism are progressive with increasing glucose intolerance. We also are attempting to determine whether the differences in parental diabetic status influence the parameters of glucose metabolism independent of changes in glucose tolerance. We are comparing in vitro adipocyte data with the in vivo data to determine whether the changes in in vitro adipocyte metabolism parallel those of in vivo glucose metabolism. The data from 50 male, glucose tolerant Indians indicate that glucose transport in the isolated adipocyte is only weakly correlated with the maximal insulin-stimulated glucose disposal rate in vivo.